CAMBRIDGE, Mass. -- After an hour-long training session at Harvard University on Friday morning, U.S. national team manager Bruce Arena said he noticed an improved sharpness. Arena had been concerned that his squad was fatigued side following two matches in three days last week, before making a cross-country flight to the East Coast from Seattle, Wash.
Now that the two- and three-day turnarounds between matches during the group play portion of the CONCACAF Gold Cup is behind them, the Americans should be at their best on Saturday afternoon when they face Jamaica in a quarterfinal matchup at Gillette Stadium in Foxboro.
Arena's experimentations with his lineup during victories over Cuba and Canada, as well as in the 0-0 draw against Costa Rica, saw 22 of the 23 players (goalkeeper Matt Reis being the other) on the roster start a match. Such tinkering is over now that the knockout round is upon them.
"Now you've got to play to win, so you put what you think is your best team out there and try to win," said the longtime U.S. manager. "We don't have any choice in the matter. There's no tomorrow."
This tournament has allowed Arena an opportunity to give looks to previously uncapped young players such as midfielder Brad Davis and forward Santino Quaranta. It's also been a chance to look at some of the veterans from the past looking to earn "regular" status once again in players like Chris Armas, Ben Olsen and Tony Sanneh.
But now that a tournament title is within the side's grasp, it's unlikely that the aforementioned players will see too much time. Instead, Arena will field a lineup on Saturday that will feature mostly players that have helped the U.S. through the past 13 months of World Cup qualification. The only two players that have not been involved in qualifying that will likely start against Jamaica are Jimmy Conrad and John O'Brien.
Since Eddie Pope is still hampered by a sprained left ankle, he is not expected to start, yet will be available on the bench. Conrad is likely to step into his spot and start as one of the two centerbacks with Oguchi Onyewu. The options at left and right back are limited since Frankie Hejduk has to sit out due to yellow card accumulation. Steve Cherundolo will continue to start at right back, while Greg Vanney will play on the left.
In the midfield, Arena has the most options, as injuries and suspensions have limited him more in the back and up top. Since O'Brien has done well in this tournament after not playing for the national team for over a two-year span, he'll be starting as a central midfielder. His likely partner will be Pablo Mastroeni. Steve Ralston and DaMarcus Beasley are expected to be on the right and left flanks, respectively, with Landon Donovan and Josh Wolff in front of them up top.
It'll be an athletic lineup with a good amount of speed, yet Arena was clear in saying that the athleticism of the Reggae Boyz makes it a situation where his side will not be looking to engage in an end-to-end, up-and-down battle against.
"It's a team that we don't want to get into a foot race with," he said.
Jamaica comes into Saturday's match after having gone 1-1-1 in Group C that includes a 1-0 loss to Mexico on Wednesday night. Had they won that match, the Reggae Boyz would have triumphed in the toughest of the three groups and not had to change venues and fly from Houston to Foxboro.
Even though Arena admitted that fatigue could be a factor for the Jamaicans, he was quick to point out that he believes they're a bit more organized and better overall as a side than they were last year when the teams tied in both semifinal round matchups.
"They've played very well in the tournament so far," he said. "Obviously, they've scored a number of goals -- I think seven goals in the three games and they've given up seven goals - so they're an interesting team, and explosive going forward."
Arena mentioned 27-year-old midfielder Jermaine Hue by name, as his emergence with the Jamaican side has been trumpeted throughout this tournament. Hue, who plays for the same club in Kingston (Harbour View) that teammate Damani Ralph and former MetroStars striker Fabian Taylor came out of, has scored two goals and has caught the eyes of several scouts with his play.
As a group, the Reggae Boyz seemingly have more on the line than the U.S. since they are no longer involved in World Cup qualifying. Combine that with the fact that they are playing a side that they feel "stole" three points from them at "The Office" in Kingston last August when Brian Ching scored a late goal to deadlock the match at 1-1, and you have a very dangerous opponent.
"They got knocked out early in qualifying," said goalkeeper Kasey Keller, "so there are definitely guys here who want to prove something, even if it is to get ready for the next round (of qualifying), so it could be a big opportunity for some of those players."
"It puts a lot more weight on this tournament for them," added Wolff. "Also, any time a team plays the U.S. these days it's a big game. In the past, it wasn't always like that."
One of the players that certainly will be fired-up for this match, in particular, is striker Damani Ralph, who left the Chicago Fire this past March to play in Russia. With his speed and one-on-one ability, he'll be a player that the U.S. defenders will have to mark closely.
"The unpredictability of the Jamaicans can put a little fear in you, and I think Damani is an example of that," said Wolff. "In MLS, maybe he didn't link up so well with other forwards, but he kind of had his mind set as soon as he got to ball that he was going straight to goal. Even if it meant beating one of two layers or shaking off a defender, he was able to do that and score some real quality goals. He's got a variety of ways of scoring.
"We have to be aware of that."
Should the U.S. get by Jamaica, they'd have four days off before having to take a drive down I-95 to Giants Stadium to take on the winner of the Honduras-Costa Rica match. The final is on July 24 at the same venue in what could end up being yet another U.S.-Mexico encounter should everything work out.
The U.S. players firmly believe getting there is within their reach.
"The way we are playing," said Keller, "our thought process is that we can win this. We had a lot of fun when we won it a few years ago."
Marc Connolly covers soccer for ESPN.com. He can be reached at email@example.com.